[B]efore we cede the entire moral penthouse to “committed vegetarians” and “strong ethical vegans,” we might consider that plants no more aspire to being stir-fried in a wok than a hog aspires to being peppercorn-studded in my Christmas clay pot. This is not meant as a trite argument or a chuckled aside. Plants are lively and seek to keep it that way. The more that scientists learn about the complexity of plants — their keen sensitivity to the environment, the speed with which they react to changes in the environment, and the extraordinary number of tricks that plants will rally to fight off attackers and solicit help from afar — the more impressed researchers become, and the less easily we can dismiss plants as so much fiberfill backdrop, passive sunlight collectors on which deer, antelope and vegans can conveniently graze. It’s time for a green revolution, a reseeding of our stubborn animal minds.

When plant biologists speak of their subjects, they use active verbs and vivid images. Plants “forage” for resources like light and soil nutrients and “anticipate” rough spots and opportunities. By analyzing the ratio of red light and far red light falling on their leaves, for example, they can sense the presence of other chlorophyllated competitors nearby and try to grow the other way. Their roots ride the underground “rhizosphere” and engage in cross-cultural and microbial trade.

“Plants are not static or silly,” said Monika Hilker of the Institute of Biology at the Free University of Berlin. “They respond to tactile cues, they recognize different wavelengths of light, they listen to chemical signals, they can even talk” through chemical signals. Touch, sight, hearing, speech. “These are sensory modalities and abilities we normally think of as only being in animals,” Dr. Hilker said.

Plants can’t run away from a threat but they can stand their ground. “They are very good at avoiding getting eaten,” said Linda Walling of the University of California, Riverside. “It’s an unusual situation where insects can overcome those defenses.” At the smallest nip to its leaves, specialized cells on the plant’s surface release chemicals to irritate the predator or sticky goo to entrap it. Genes in the plant’s DNA are activated to wage systemwide chemical warfare, the plant’s version of an immune response. We need terpenes, alkaloids, phenolics — let’s move.

(Strong emphasis added.)

There are more examples in the article about the fascinating ways plants respond to their environments.

Now, I don’t think the plant biologists are arguing that plants have minds or self-awareness or capacities of that sort. I’m not even sure that the plant-powers described in the article add up to a capacity to feel pain. But “touch, sight, hearing, and speech” suggest a more active engagement with their surroundings that we’re used to acknowledging.

Whatever plants are up to, you could argue that they’re not hitting the level of sensory modalities and abilities that animals do (or at least, the animals that humans are likely to eat — surely there are some members of the animal kingdom that won’t rise much above the level of the plants).

But this mirrors the argument that the sensory modalities and abilities of animals, while similar to those of humans, fall short and put non-human animals at a relevantly different level. Usually, the line-drawing (or arguing against line-drawing) between humans and non-human animals is cast in terms of the differences in their cognitive capacities (or in the existence of a continuum in cognitive capacities between them).

Technically, since they don’t have brains, plants can’t have any cognitive capacities. But if they manage to have sensory modalities and abilities normally thought of as only being in animals without needing brains, should we really hold their lack of brains against them in our line-drawing?

Because, when it comes to line-drawing about organisms that are potentially nourishing and tasty, the question people often want to answer is “Would it be ethical for me to eat the organisms on this side of the line? Would it be unethical for me to eat the organisms on that side of the line?” If we can’t (ethically) eat animals because they share particular capacities with humans — making them not identical to us, but similar in a morally relevant way — then what should we make of the recognition that plants have capacities of the same sort that put them on the continuum with non-human animals and with us?

Comments

What to eat it? Then you should be willing and able to grow it and kill it. Not necessarily every day and all the time but at least knowing enough that you know how much/what kind of effort goes into your food.

Letting someone else do the “dirty” work – often under poor conditions (any way you define poor) so that you can have your dinner is never an ethical choice.

It seems to me that the relevant biological characteristic that implicates ethics at all in determining what we should or shouldn’t do to other organisms is the capacity for suffering. If an organism has the capacity to suffer, then we ought to take this into account in assessing our own actions vis a vis that organism. If an organism cannot suffer, then there is no moral dimension that relates to the interests of that organism.

This is why there is no moral calculus involved in smashing the shit out of cockroaches in my house, while there is one involved in deciding how to deal with rodent infestations.

CCP – Please explain how you know that cockroaches cannot suffer. I’m really hopeful that whatever explantation you come up with will generalize to flies, since I’d love to be able to pull their wings off without myself having to suffer what are called “pangs of conscience.”

It should be quite obvious that what you wrote was not clear and certainly does not approach the clarity of crystal or I would not be asking, CPP. Perhaps you should try composing your thoughts again, more slowly this time.

It’s really all about trophic levels. If I assume that eating animals is similar to eating plants I simply consume more plant material by consuming the animal. Show me some plants, used as food sources, that are secondary or tertiary consumers and I’ll have a moral conundrum. Until then the ethical choice is relatively clear if you choose to make food consumption an ethical issue.

If an organism cannot suffer, then there is no moral dimension that relates to the interests of that organism.

What about that organism’s right to exist? Or any crucial role it plays in its local environment? Let me additionally restrict my questions to an organism that is of no use to humans as food or for any other pragmatic purpose.

What about the definition of cognition requires a brain? I ask only because it’s not a field I know a lot about, but it seems like if we literally define cognition as a thing that brains do, then we’re prejudging important questions about, for instance, artificial intelligence and the cognitive abilities of alien life.

If the issue is the lack of a central unit for organizing sensory data, you still get into problematic realms. Jellyfish and hydras aren’t exactly smart, but their neural networks can do fancy things, as can the decentralized processing power of an ant nest or beehive. The internal feedback network of a plant can, with sufficient effort, surely be sensibly analogized to animal systems where cognition is uncontroversial.

cue music
I’ve heard the screams of the vegetables (scream, scream, scream)
Watching their skins being peeled (having their insides revealed)
Grated and steamed with no mercy (burning off calories)
How do you think that feels (bet it hurts really bad)
Carrot juice constitutes murder (and that’s a real crime)
Greenhouses prisons for slaves (let my vegetables go)
It’s time to stop all this gardening (it’s dirty as hell)
Let’s call a spade a spade (is a spade is a spade is a spade)

CPP – My question wasn’t meant to elicit a solution to the problem of global skepticism. Frankly, given the terms in which you choose to address my query, I don’t know that _you_ are capable of suffering. So if that’s your game, it ought to be OK for me to dismember you. Is that right?

It’s important to consider that sometimes plants want to be eaten – in the case of fruit for example. Of course this is true of some parasitic animals also, but in that case they are not eaten intentionally or for nutrition.

Also, because of the plant body’s indeterminate, modular construction even crucial organs such as stems and leaves can regrow even in “higher” plants. In nature grazing is only sometimes fatal. Usually in order to eat an animal we have to kill it first. Even if we are only interested in part of it (eg a shark’s fin) we have to sacrifice the whole animal.

If you were to collapse while feeding the chickens, would the chickens forgo eating your carcass? If you slipped and fell breaking your leg in the pig sty, and were unable to escape, would the 600 lb yorkshire white boar help you out or chow down on your still twitching leg?
As a previous farmer I eat nearly everything – and I mean everything. I didn’t spend months raising that animal only to eat the prime parts. (I love hog jowl, best part of the barbeque in my opinion.) I agree knowing the animal up close and personal is the best way, but they frown upon urban gardening, let alone urban animal husbandry. I’d like to see a few less people on the planet too… (I’m working on making cancer communicable…)

Michael Pollan seems to imply that, at least that they have a cushiesr life than any other garden plant, tended by animal ‘slaves’ more devoted than any insect pollinator, however we do end up smoking sexually frustrated females – not sure how much they ‘like’ that!